Development Of Displacement-Measurement System For Cold Components In EAST

The EAST superconducting Tokamak is one of the momentous engineering in national ninth five-year project. It aims to construct a large-scale superconducting Tokamak device with non-circular section, establish many kinds of techniques demanded for steady-state operation of this device, and make experiment researches on the basic physics problems of future reactors with security and high efficiency.Magnet and thermal shield are key parts in the EAST superconducting Tokamak device. Because they are working at low temperature, it is very important to monitor their displacements during the cooling process for ensuring their placement can match the preset requests after cooling.In this study, the displacement-measurement method was investigated by real-time monitoring the displacement of cold components, and the metrical method of displacement transfer was selected finally. Meanwhile, Magnet and thermal shield were analyzed by using FEM, then their deformation and displacement were obtained. Combining correlated experiment data, the error in every part of this system was corrected and the structural design of displacement-measurement was fulfilled.During the cooling experiment, the metrical data were collected by computer program. Comparing with the results of theoretical calculation, the displacement change and potential errors when cooling were acquired, and the improved method for this system was put forward.Using the displacement transfer measurement, the displacement of cold components in EAST was measured successfully while cooling down. It not only contributes to the EAST project, but also accumulates technical supports for research on the homogeneous Tokamak devices and other cryogenic equipments.